I'm not trying to argue over Vortecs they are better heads. I'n just wanting to know how good the 291's can be. I think the OP would like to know that as well. I know vortecs can take a 2.08" intake valve an flow around 280 with that. What can the 291's take? The 291's can take more milling and have a standard intake pattern.

Any head that you mill a lot will need to have the intake machined accordingly, again, we're back to $$ per HP.
The 291 is BY FAR a better choice for the application than the 882. The 291 is also worth a lot more to a restorer than to a HP junkie.

The thing is, he could probably off the 291s and the 882s on Ebay or Craigslist for enough to buy a pair of Vortecs (which often come with valve covers and rocker arms).

Im sorry guy but all I really wanted to know was about 291s I have 50.00 in the pair. Vortec heads I said nothing about and no I will not buy Vortec I want double hump. Sorry for asking about 291s. I like double humps and I will roll on with them!!!

I'm not trying to argue over Vortecs they are better heads. I'n just wanting to know how good the 291's can be. I think the OP would like to know that as well. I know vortecs can take a 2.08" intake valve an flow around 280 with that. What can the 291's take? The 291's can take more milling and have a standard intake pattern.

You could stuff a 2.08" in there if you want, but it really isn't the best idea. You can't releive the chamber around that valve size enough to make it really pay off, you will make the casting too thin and it will crack from the chamber to the cooling hole in the deck, about 3/8" or so toward the intake valve side from the sparkplug. They will also have problems with cracking in the narrow area between the valve seats.

2.055" is the largest you can go and expect any durability, and sometimes it will still crack between the seats.

The 291 can be a good head, but like all "Fuelies" be prepared to spend 25+hours with a carbide burr and a die grinder in your hand, there is a lot of metal to be removed considering you are starting with a 160-162cc intake port that you need to get up into the 180+ area to see big power from.

Like Rickracer said, unless you can do all that porting yourself they are a step on the wrong direction. Sure, they worked for years, but that was because that was all there was, Fuelies went on my "sell to the uneducated" list as soon as the Dart Sportsman head was released in the 80's.

For the cost of just the basic rebuild machine work and parts on the Fuelies, you could be buying a brand new set of World SR Torquer, RHS Pro Torker, or the EQ Iron and be farther ahead. Still got to do some porting but not near as much as the Fuelie needs.

You can even get entry level aluminum like ProComp or Patriot for that money, and be ahead of the Fuelies. Just buy them bare so you can pick the quality of the components in them, the basic castings are fine, just need a slight blending in the ports, it is the crap parts they use to assemble them that has given them a bad name.

OP wants to have some fun street/strip? Gonna leave hp on the table after spending beacoup bucks going with either of his heads. I know the truth can hurt and is hard to accept but it's been pointed out over and over. As always, do what you want. It's your car and your dough. When you get dusted by a modern headed engine, don't come crying back here.

A mild-port on a 291 will flow as well as a Vortec. It takes great gobs of work and money to make big hp with any of those heads. You do need the 2.02/1.6 valves, and the bowl blending to go with them. Even with flat tops you may have too much compression for pump gas. Later on when you want to go faster, get some EngineQuest heads with 50cc chambers that will flow 600hp out of the box and right now cost about the same as Vortecs.

Just grab the stock valve covers and self-aligning rocker arms to go with the heads. I bought OEM covers for mine, used, for $25. New OEM GM self-aligning rockers are $60. Valve spring change, about $75.

Although that is true, the stock rocker covers will not clear many aftermarket roller rockers.

Im sorry guy but all I really wanted to know was about 291s I have 50.00 in the pair. Vortec heads I said nothing about and no I will not buy Vortec I want double hump. Sorry for asking about 291s. I like double humps and I will roll on with them!!!

I don't think anybody's gonna be mad at you TG, I, and a few others, just wanted you to go into this with open eyes, knowing what all your viable options are. You chose the 291s, so run with it, chances are you won't really be disappointed,

Thank you. This is my first build. Im loving it. I have a S10 this motor is going in. It had a 355 when I bought it but not a mean one. So now since my father has passed I asked another guy to help me out. If I would of known about Vortec heads before I bought both sets of these I would probably run that way. I have TRW l3026F pistons now Im deciding which cam to go with. Thinking 303 525 but not sure. I take my stuff to John Phillips on Wensday and he will discuss with me where to go i guess. I can not wait to get this all done. I also have 456 gears with mini spool th350 with manual valve body with a massive shift kit, B&M qiuck silver slap shift. It should be decently fast. Its for road and the strip. Im 34 and love racing. I also have Weld drag lights front and rear with Mickey thompson Sportsmans 29x12.50x15 and 15x5 fronts I believe they are. Thanks again for all of your minds.

I spun a bearing in my '93 4.3 S10 shortbed Friday night, (drag racing it at the 1/8 drags), so guess what's going it in now? The same 360, (.060 350), that was in my 82 longbed, but it was a fair bit milder then. It's an all forged flat top bottom end, balanced, zero decked, and it had a self ported pair of 882s on it, Summit 1105 cam, Strip Dominator and a 700 DP. It's getting freshened up with a Comp solid roller, a pair of mildly ported, stainless valved Vortecs, a Vortec RPM Air Gap, and a 650 DP. This swap has been in the planning stage for a couple of years now, gathering parts, beefing up the rear, tricking out a BeCool radiator for it, doing an LS Camaro brake swap up front, 2000 Blazer discs in the rear, tubular upper A-arms, and the 4L60 trans is now freshened up to replace the 4L60E. It will get a posi, disc brake, narrowed and pinion centered 3.55 8.8 pretty soon as well. My goals are 22+ mpg, 400++ hp, and low 12s or better in the 1/4, w/o N2O, which it will have as well.
The previous combo got 18+ mpg with the same 4L60 and a 2800 stall lockup converter, as mismatched as it was. I got the bottom end mostly built, planning a 500+ hp roller cam, aluminum head motor, then wound up in a divorce and just threw it the rest of the way together with stuff I had handy and/or cheap, like the Summit cam. It's gonna be a different beast this time though,

Although that is true, the stock rocker covers will not clear many aftermarket roller rockers.

True. But IIRC, the 1.6 ratio rockers GM uses on some of their crate engines (designed by Crane?) will fit the stock center bolt covers, you have to be specific on what valve covers you want to use the rockers with- not all roller rockers will fit, even at 1.5:1 ratio.

Obviously, there's the option of using extra thick or doubled gaskets to gain some extra clearance, or buying or fabricating a spacer.

There are adapter$ that allows perimeter v-covers to fit center bolt heads:

But what I haven't seen (nor looked very hard for) is a spacer to use on the center bolt covers that raises them up.

The thumbnail drawing of a valve cover spacer is for the older perimeter style heads, added just because I could- it may come in handy to someone, who knows. Unfortunately I do not know who to credit it to, sorry.

Hi I just wanted to give a lil update of my new motor build. I went ahead and used the 3917291 heads and had them fully ported and polished,milled and 3 angle valve job now 58-60cc and reshaped where valves are.. I have a Holley 750 double pumper,Vic jr intake with Nitrous plate,Comp Cams magnum 294s flat tappet solid cam,Lunati Voodoo 1.5 roller rockers,.060 over pistons 10.5:1 at 64cc (now 58-60cc). Comp cams double roller timing chain, Got NX 10lb bottle can go from 50-250 hp. Proform electric water pump, bottom mount alternator, aluminum radiator, tranny cooler, new rebuilt th350 with shift kit, 10 bolt 8.5 456 rear end. All mallory ignition, shift light tach and this is going to be driven on street and strip, Its a short bed S10 with Weld drag lites with Mickey thompson pro sportsmans 29x12.50x15 rear and 4.5 weld draglites front runners. Everything is brand new except motor block and head casting. My truck weighs 2640 any recommendation on what I might run in the 8th? And what compression I might have? Thanks

Congratz on getting it going man and it sounds like it will be awesome! It ought to fly! Can you tell what the specs of the cam are? I may be able to estimate the compression ratio using software eap pro

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